xref: /illumos-gate/usr/src/uts/common/xen/io/blkif_impl.h (revision 55fea89d)
1 /*
2  * Permission is hereby granted, free of charge, to any person obtaining a copy
3  * of this software and associated documentation files (the "Software"), to
4  * deal in the Software without restriction, including without limitation the
5  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
6  * sell copies of the Software, and to permit persons to whom the Software is
7  * furnished to do so, subject to the following conditions:
8  *
9  * The above copyright notice and this permission notice shall be included in
10  * all copies or substantial portions of the Software.
11  *
12  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
13  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
14  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
15  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
16  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
17  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
18  * DEALINGS IN THE SOFTWARE.
19  */
20 #ifndef __XEN_BLKIF_H__
21 #define __XEN_BLKIF_H__
22 
23 #include <public/io/ring.h>
24 #include <public/io/blkif.h>
25 #include <public/io/protocols.h>
26 
27 /* Not a real protocol.  Used to generate ring structs which contain
28  * the elements common to all protocols only.  This way we get a
29  * compiler-checkable way to use common struct elements, so we can
30  * avoid using switch(protocol) in a number of places.  */
31 
32 /* i386 protocol version */
33 
34 #pragma pack(4)
35 
36 struct blkif_x86_32_request {
37 	uint8_t        operation;    /* BLKIF_OP_???                         */
38 	uint8_t        nr_segments;  /* number of segments                   */
39 	blkif_vdev_t   handle;       /* only for read/write requests         */
40 	uint64_t       id;           /* private guest value, echoed in resp  */
41 	blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
42 	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
43 };
44 struct blkif_x86_32_response {
45 	uint64_t        id;              /* copied from request */
46 	uint8_t         operation;       /* copied from request */
47 	int16_t         status;          /* BLKIF_RSP_???       */
48 };
49 typedef struct blkif_x86_32_request blkif_x86_32_request_t;
50 typedef struct blkif_x86_32_response blkif_x86_32_response_t;
51 
52 #pragma pack()
53 
54 /* x86_64 protocol version */
55 struct blkif_x86_64_request {
56 	uint8_t        operation;    /* BLKIF_OP_???                         */
57 	uint8_t        nr_segments;  /* number of segments                   */
58 	blkif_vdev_t   handle;       /* only for read/write requests         */
59 #if defined(__GNUC__)
60 	uint64_t       __attribute__((__aligned__(8))) id;
61 #else
62 	uint8_t        pad[4];
63 	uint64_t       id;
64 #endif
65 	blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
66 	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
67 };
68 struct blkif_x86_64_response {
69 #if defined(__GNUC__)
70 	uint64_t       __attribute__((__aligned__(8))) id;
71 #else
72 	uint64_t       id;
73 #endif
74 	uint8_t         operation;       /* copied from request */
75 	int16_t         status;          /* BLKIF_RSP_???       */
76 };
77 typedef struct blkif_x86_64_request blkif_x86_64_request_t;
78 typedef struct blkif_x86_64_response blkif_x86_64_response_t;
79 
80 DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request, struct blkif_x86_32_response);
81 DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request, struct blkif_x86_64_response);
82 
83 enum blkif_protocol {
84 	BLKIF_PROTOCOL_NATIVE = 1,
85 	BLKIF_PROTOCOL_X86_32 = 2,
86 	BLKIF_PROTOCOL_X86_64 = 3,
87 };
88 
89 #define	BLKIF_RING_SIZE	\
90 	__RING_SIZE((blkif_sring_t *)NULL, PAGESIZE)
91 #define	BLKIF_X86_32_RING_SIZE \
92 	__RING_SIZE((blkif_x86_32_sring_t *)NULL, PAGESIZE)
93 #define	BLKIF_X86_64_RING_SIZE \
94 	__RING_SIZE((blkif_x86_64_sring_t *)NULL, PAGESIZE)
95 
96 #endif /* __XEN_BLKIF_H__ */
97